I have knowledge of html and css but not php. In a website template that I had downloaded it had the following codw in the header.php file. Can someone please explain to me if it is malicious, what it means or what it is commanding? The code is:

just faced the exact same problem.the solution is quite simple.. just delete that php code! Yes that's right--> select code. ctrl+x. Update File.Just did it myself and it works like a beauty! Website loads much much faster also.

oh! i almost forgot! if for any reason things don't go as planned--> go to the same place in the file. ctrl+v. Update File

IMHO it is suspicious and using this way (lets say if it is legal site but hacked and that .js files spoofed)that guys can infect your site visitors+exploit some 0day vulnerabilities against Flash players+Java Plugins+redirect to malware domains+Phish+DDOS another sites using your Real Visitors UA+IP(because it has advantages!) and Finally create BOTNET from your site visitors.

<img src="data:image/gif;base64,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"></img>It also calculates how much "online users"